Metallurgical vessel

ABSTRACT

Metallurgical vessel for iron and steel making including a bottom portion, a sidewall and a lance arrangement of at least two lances for supplying oxygen containing gas to the interior of the vessel in operation. Each lance includes an end portion for emitting oxygen containing gas. The lance arrangement is configured so as to achieve in operation a substantially downwardly directed flow of post-combusted gases at the side wall of the vessel and a substantially upwardly directed flow of post-combusted gases in the center of the vessel.

The present invention relates to a metallurgical vessel for iron andsteel making comprising a bottom portion, a sidewall and a lancearrangement of at least two lances for supplying oxygen containing gasto the interior of the vessel in operation wherein each lance comprisesan end portion for emitting oxygen containing gas. The present inventionalso relates to methods of iron making.

The object of the present invention is to provide a metallurgical vesselwhich can be used on a large scale with increased production efficiencyand reduced clogging of equipment positioned in a roof portion of thevessel.

The present invention improves on the prior art as the lance arrangementis configured so as to achieve in operation a substantially downwardlydirected flow of post-combusted gases at the side wall of the vessel anda substantially upwardly directed flow of post-combusted gases in thecentre of the vessel.

The term post-combusted gases refers to the gases which are producedduring reactions in the metallurgical vessel and are subsequently atleast partially post combusted. The term centre of the vessel refers tothe central column area of the vessel surrounding and including thecentral axis of the vessel. When the metallurgical vessel is upright thecentral axis extends essentially vertically through the centre of thevessel.

The present invention has the considerable advantage that it can besuccessfully used for vessels of large diameter by stimulating what hasbeen found to be a very favourable gas flow in the body of the vessel.The gas flow results in reduced heat loads on the walls whilst theplurality of lances ensure a good distribution of oxygen containing gasand therefore good heat distribution over the vessel area, therebyincreasing production efficiency. The present invention also mitigatesthe problem of clogging of and damage to, e.g. ports, seals, sensors andmeasuring equipment positioned in the roof portion of the vessel whichare expensive and difficult to replace or repair. This problem ofclogging arises when particulates are entrained in the upward flow ofpost combusted gases directed to the roof portion of the vessel. Thelance configuration of the present invention creates a substantiallydownward flow of post combusted gases at the sidewall whilst thesubstantially upwardly directed flow occurs at the centre of the vessel.Any particulates entrained in the upward flow therefore pass up thecentre of the vessel and have less chance of coming into contact withany of the equipment, ports, seals or sensors projecting through theroof. Examples of processes for producing molten metal directly frommetal oxides include the use of electric furnaces as the major source ofenergy for the smelting reactions, the Romelt process, the DIOS process,the AISI process, the Hismelt process and using a cyclone convertorfurnace.

EP 0 735 146 discloses a metallurgical vessel of the converter type inwhich pre-reduced iron ore undergoes a final reduction. The bottomportion of the metallurgical vessel contains the iron bath whilst thewall or side wall extends upwardly from the bottom portion, enclosingthe slag layer. The roof portion extends from the top of the sidewallover the interior of the vessel and connects with the melting cyclone. Aplurality of lances project through the wall of the metallurgical vesseland supply oxygen to the interior of the vessel. The lances arespecified as being orientated vertically as much as possible in order toachieve the same effect as when using a central lance.

As mentioned above the present invention improves on the prior art asthe lances are configured so as to achieve in operation a substantiallydownwardly directed flow of post-combusted gases at the side wall of thevessel and a substantially upwardly directed flow of post-combustedgases in the centre of the vessel. The substantially downwardly directedflow of post-combusted gases at the side wall of the vessel and asubstantially upwardly directed flow of post-combusted gases in thecentre of the vessel achieved in operation can be directly andpositively verified by a person skilled in the art by, for example,calculating and monitoring the heat losses per square metre in the sidewall and roof portion of the vessel.

The side walls and roof section of a metallurgical vessel may comprisemetal staves or tubes through which water flows for the purpose ofcooling the vessel and/or refractory material that can withstand hightemperatures. The side wall and roof section of a metallurgical vesselare usually equipped with temperature sensors.

The temperature sensors may be thermocouples that measure the coolingwater temperature or thermocouples that measure the refractory walltemperature in various parts along the height and circumference of theside wall and roof portions of the vessel. When the cooling watertemperature measurement is combined with a cooling water flowmeasurement, a person skilled in the art can calculate and monitor theheat losses per square meter (heat fluxes) in different parts along theheight and circumference of the side wall and roof portions of thevessel. The skilled person can thus verify whether there is in operationa substantially downwardly directed flow of post-combusted gases at theside wall of the vessel and a substantially upwardly directed flow ofpost-combusted gases in the centre of the vessel by monitoring the sidewall and roof portion temperatures of the vessel.

In a conventional metallurgical vessel with a single central lance orvertically orientated lances the combustion created by the lance(s),creates a strong expansion of gases in the centre of the vessel thatleads to a flow of hot combustion off gases towards and up the sidewalls.

In a metallurgical vessel according to the present invention thesubstantially downwardly directed flow of post-combusted gases at theside wall of the vessel has a cooling effect on the side wall and thusresults in lower refractory temperatures or heat fluxes. The hot postcombusted gases flow substantially upwardly through the centre of thevessel and thus do not contact the side wall. The present invention alsoresults in a decrease in refractory temperatures or heat fluxesparticularly in the area of the side wall in the vicinity of the lances.

In the metallurgical vessel of the present invention at least one of thelances may be provided with means for emitting a plurality of jets ofoxygen containing gas from its end portion. Such a lance can emit oxygenover a wider surface area of the contents of the vessel compared to asingle jet Each of the lances may be provided with means for emitting aplurality of jets of oxygen containing gas from its end portion.

The lances are preferably configured with at least one of the lancesprojecting through the roof portion of the metallurgical vessel. Theroof portion of the vessel extends from the top of the sidewall. If amelting cyclone is positioned above and in open communication with thevessel then the roof portion extends from the top of the sidewall to themelting cyclone. At least one of the lances thus penetrates through partof the vessel that does not come into contact with the contents of thevessel thereby avoiding damage to the seal around the lance at the pointit penetrates the vessel. Each of the lances may project through a roofportion of the metallurgical vessel.

At least one lance is preferably arranged to direct the oxygencontaining gas inwards towards the central axis of the metallurgicalvessel. Each of the lances may be arranged to direct the oxygencontaining gas inwards towards the central axis of the metallurgicalvessel. Directing the gas inwards towards the central axis of the vesselcreates an area of low pressure at the lance end portion resulting inpost combusted gas being entrained downward at the sidewall towards theend portion of the lance whilst an upward flow of post combusted gas isgenerated up through the centre of the vessel.

At least one of the lances may be inclined from the vertical under afirst acute angle with its end portion inclined towards the central axisof the metallurgical vessel. Inclining a lance directs the oxygencontaining gas inwards towards the central axis of the metallurgicalvessel and improves the distribution of oxygen containing gas over thesurface of the contents of the vessel. Each of the lances may beinclined from the vertical with its end portion inclined towards thecentral axis of the metallurgical vessel.

The end portion of at least one lance may also be configured to directthe oxygen containing gas towards the central axis of the metallurgicalvessel under a second acute angle from the vertical which second acuteis greater than the first acute angle. The greater angle from thevertical than the angle of inclination of the lance increases the upwardand downward gas flow generated in the vessel. Each of the lances may beconfigured to direct the oxygen containing gas towards the central axisof the metallurgical vessel at a greater angle from the vertical thanthe angle of inclination of the lance.

The lances may be adjustable in height and therefore able to bepositioned at an optimal height over the surface of the of the vesselcontents when the vessel is at varying levels of fullness. The angle ofinclination of the lances may also be adjustable to enable thedistribution of oxygen containing gas over the surface of the contentsof the vessel to be optimised.

The lance end portions may all be positioned at an equal distance fromthe sidewall to achieve the most effective heat distribution over thesurface of the vessel contents to maximise production efficiency.Preferably three or more lances supply oxygen containing gas to thecontents of the vessel to ensure optimum heat distribution andproduction efficiency.

Particulate material may preferably be added to the metallurgical vesselvia at least one feed chute in the substantially downwardly directedflow of post-combined gases which feed chute is positioned at a shortdistance from the lances. The substantially downward gas flow in thevicinity of the sidewall thus entrains the particulate material in theform of e.g. coal fines and transports it down towards the end portionsof the oxygen lances and the slag layer. This avoids the problem of asignificant proportion of any particulate material added to the vesselbeing lost, due to particles being entrained in the upward gas flow,before reacting with the contents of the vessel. The preferredembodiment thus results in a significantly lower loss of particulatematerial, such as coal fines, from the vessel and a higher productionefficiency as a greater proportion of the particulate material isavailable as a reactant. The gas leaving the metallurgical vessel inoperation (off gas) can be sampled, as is known in the art, to verifythe reduction in particulate material in the off gas. The combustiondegree of the off gas will also improve as the coal pyrolysis products,which evolve spontaneously when coal comes into the hot atmosphereinside the metallurgical vessel during operation, will be entrained inthe downward flow of gas at the side wall and will be combusted ratherthan being blown out of the vessel. The combustion degree of the off gascan also be ascertained by off gas sampling and analysis as is known inthe art.

The loss of particulate material is further minimised if each lance hasa corresponding feed chute so that the particulate material addedthrough the chute is entrained into the substantially downward gas flow.The optimal position for each chute is to be positioned between thelance and the sidewall of the metallurgical vessel, in a radialdirection, where the substantially downward flow of the post combustedgases is at a maximum.

The sidewall of the vessel preferably comprises a lower portion foraccommodating a molten metal bath and part of a slag layer in use and anupper portion for accommodating the remainder of the slag layer in use,wherein the at least two lances project into the upper portion of thevessel and supply oxygen containing gas to the upper portion of thevessel and wherein a plurality of tuyeres are arranged around thecircumference of the lower portion of the vessel suitable for supplyinggas and/or liquid and/or solids and/or plasma into the slag layer in thelower portion of the vessel. The at least two lances supply oxygencontaining gas, and thereby heat, to the slag in the upper portion ofthe vessel whilst the gas and/or liquid and/or solids and/or plasmasupplied by the tuyeres ensure that the lower slag layer does not becomequiescent. Quiescence results in a cooling of the lower slag layer and aloss of productivity.

The tuyeres supply gas and/or liquid and/or solids and/or plasmadirectly to the lower slag layer whereas gas is injected through thebottom of the vessel into the molten metal in bottom stirring. Thepreferable aspect of the invention thus does not generate high flowvelocities in the molten metal thereby avoiding one of the majordrawbacks of bottom stirring namely the fast erosion of the vessel wallin the part of the vessel containing the molten metal. The supply of gasand/or liquid and/or solids and/or plasma to the slag layer in the lowerportion of the vessel by the tuyeres thus does not cause erosion of therefractory lining in the hot metal zone but it does maintainproductivity by stirring the lower slag layer. Stirring the lower slaglayer maximises reactions within the lower slag layer and ensures itdoes not become quiescent. The supply of combustible gas and/or liquidand/or solids by the tuyeres also increases heat transfer from the slaglayer to the molten metal in the lower portion of the vessel. Thetuyeres are also easier to maintain as they are positioned above the taplevel of the vessel.

The diameter of the lower portion of the metallurgical vessel ispreferably smaller than that of the upper portion. The tuyeres arearranged around the circumference of the lower part of the vessel andtherefore the jets emitted by the tuyeres will penetrate into the slaglayer in the lower portion of the vessel before rising through the slaginto the upper portion of the vessel. Any “hot spots” i.e. areas ofhigher temperature, created by the gas and/or liquid and/or solidsand/or plasma supplied by the tuyeres, in the slag layer in the upperportion of the vessel will therefore be sufficiently distant from thewall of the vessel to ensure that no increase in corrosion and/orerosion of the wall occurs.

The tuyeres may preferably comprise oxy-fuel burners to act as a directheat source in the slag layer in the lower portion of the vessel. Theoxy-fuel burners will increase the productivity of the reactor byincreasing the occurrence of the endothermic reduction reactions andthereby increasing the reduction capacity of the slag layer.

The metallurgical vessel of the present invention preferably comprises amelting cyclone positioned above, and in open communication with, thevessel. None of the oxygen lances thus has to withstand the heat andcorrosive environment of the cyclone as they do not extend through thecyclone. Such a melting cyclone is disclosed in Dutch patent NL C 257692and EP 0735146.

The lances are preferably positioned to avoid contact with moltenmaterial passing downwards from the melting cyclone to the metallurgicalvessel so that the molten material does not damage the lances.Replacement and/or repair of damaged lances is costly and reducesproduction efficiency.

The present invention also relates to a method of reducing iron oxideinto iron using a metallurgical vessel in accordance with the inventionand comprising the steps of supplying iron oxides to the vessel andreducing the iron oxides by supplying carbonaceous material to thevessel and supplying oxygen containing gas to the iron oxides vialances. The oxygen containing gas may be supplied to the upper portionof the metallurgical vessel via the lances, and gas and/or liquid and/orsolids and/or plasma may be supplied into the slag layer in the lowerportion of the vessel via the plurality of tuyeres.

The present invention also relates to a method of iron making comprisingthe steps of:

-   -   conveying iron oxide or pre-reduced iron oxide into a        metallurgical vessel,    -   supplying oxygen containing gas to the metallurgical vessel via        a lance arrangement of at least two lances configured so as to        achieve in operation a substantially downwardly directed flow of        post-combusted gases at the side wall of the vessel and a        substantially upwardly directed flow of post-combusted gases in        the centre of the vessel,    -   supplying carbonaceous material to the vessel.        The present invention also relates to a method of iron making in        accordance with the method above comprising the steps of:    -   conveying iron-oxide containing material into a melting cyclone,    -   pre-reducing said iron-oxide containing material by means of        reducing post combusted gases originating from the metallurgical        vessel,    -   at least partly melting the iron-oxide containing material in        the melting cyclone by supplying oxygen containing gas to the        melting cyclone and effecting a further post combustion in said        reducing post combusted gases,    -   permitting the pre-reduced and at least partly melted iron-oxide        containing material to pass downwardly from said melting cyclone        into the metallurgical vessel in which final reduction takes        place and    -   effecting the final reduction in the metallurgical vessel in a        slag layer by supplying oxygen containing gas to the        metallurgical vessel, via the lances, and supplying coal to the        metallurgical vessel and thereby forming a reducing gas and        effecting at least partial post combustion in said reducing gas        in said metallurgical vessel by means of said oxygen containing        gas supplied thereto.        The present invention preferably relates to a method of iron        making as set out above including the step of:    -   supplying gas and/or liquid and/or solids and/or plasma into a        slag layer in a lower portion of the vessel.        An alternative metallurgical vessel may comprise a lower portion        for accommodating a molten metal bath and part of a slag layer        in use, an upper portion for accommodating the remainder of the        slag layer in use and a plurality of lances which project into        the upper portion of the vessel and supply oxygen containing gas        to the upper portion of the vessel characterised in that a        plurality of tuyeres are arranged around the circumference of        the lower portion of the vessel suitable for supplying gas        and/or liquid and/or solids and/or plasma into the slag layer in        the lower portion of the vessel.

The plurality of lances supply oxygen containing gas, and thereby heat,to the slag in the upper portion of the vessel whilst the gas and/orliquid and/or solids and/or plasma supplied by the tuyeres ensure thatthe lower slag layer does not become quiescent. Quiescence results in acooling of the lower slag layer and a loss of productivity. The tuyeressupply gas and/or liquid and/or solids and/or plasma directly to thelower slag layer whereas gas is injected through the bottom of thevessel into the molten metal in bottom stirring. The preferable aspectof the invention thus does not generate high flow velocities in themolten metal thereby avoiding one of the major drawbacks of bottomstirring namely the fast erosion of the vessel wall in the part of thevessel containing the molten metal.

The supply of gas and/or liquid and/or solids and/or plasma to the slaglayer in the lower portion of the vessel by the tuyeres thus does notcause erosion of the refractory lining in the hot metal zone but it doesmaintain productivity by stirring the lower slag layer. Stirring thelower slag layer maximises reactions within the lower slag layer andensures it does not become quiescent. The supply of combustible gasand/or liquid and/or solids by the tuyeres also increases heat transferfrom the slag layer to the molten metal in the lower portion of thevessel. The tuyeres are also easier to maintain as they are positionedabove the tap level of the vessel.

The diameter of the lower portion of the metallurgical vessel ispreferably smaller than that of the upper portion. The tuyeres arearranged around the circumference of the lower part of the vessel andtherefore the jets emitted by the tuyeres will penetrate into the slaglayer in the lower portion of the vessel before rising through the slaginto the upper portion of the vessel. Any “hot spots” i.e. areas ofhigher temperature, created by the gas and/or liquid and/or solidsand/or plasma supplied by the tuyeres, in the slag layer in the upperportion of the vessel will therefore be sufficiently distant from thewall of the vessel to ensure that no increase in corrosion and/orerosion of the wall occurs.

The tuyeres may preferably comprise oxy-fuel burners to act as a directheat source in the slag layer in the lower portion of the vessel. Theoxy-fuel burners will increase the productivity of the reactor byincreasing the occurrence of the endothermic reduction reactions andthereby increasing the reduction capacity of the slag layer.

BRIEF INTRODUCTION TO THE DRAWINGS

Embodiments of the invention will now be described by way ofnon-limitative examples, with reference to the accompanying drawings, inwhich:

FIG. 1 shows an apparatus in accordance with the invention.

FIG. 2 shows a view along axis “A” of FIG. 1.

FIG. 3 shows a simulation of a section of the apparatus with one lanceprojecting into the vessel section and shows the simulated trajectory ofcoal particles added at a short distance from the lance.

FIG. 4 shows simulation of a section of the apparatus with one lanceprojecting into the vessel section and shows the simulated trajectory ofcoal particles added between the lances.

FIG. 5 shows a lance end portion having four ports for emitting fourjets of oxygen containing gas.

FIG. 6 shows a particular embodiment of the invention.

FIG. 7 shows the alternative metallurgical vessel.

DESCRIPTION OF A PREFERRED EMBODIMENT

The apparatus in FIG. 1 comprises a metallurgical vessel 1, a meltingcyclone 2 (details not shown) and a plurality of lances 3, of which twoare shown. More lances may be used depending on, for example, the sizeof the vessel and the performance parameters of the lances. Themetallurgical vessel itself comprises a bottom portion 4, a sidewall 5and a roof portion 6 which extends from the top of the sidewall 5 to themelting cyclone 2. The metallurgical vessel contains an iron bath 11with a slag layer 10 on top and the vessel comprises at least one taphole 19 for tapping off molten iron and slag.

Oxygen containing gas is supplied to the interior of the vessel by thelances 3 which acts to finally reduce the pre-reduced iron oxide in theslag layer. During the final reduction a process gas comprising reducingcarbon monoxide is produced and at least partially combusted above theslag layer 10, thereby releasing heat needed for the final reduction.The at least partially post combusted gas resulting from the postcombustion is referred to as post combusted gas. Particulate coal issupplied to the interior of the vessel 1 via the feed chutes 12. Thelances 3 project into the vessel through the roof 6 and are configuredto create a substantially downwardly directed flow of the post-combustedgas at the sidewall 5 of the vessel and a substantially upwardlydirected flow of post combusted gas in the centre of the vessel 9. Theupwardly directed post combusted gas, comprising reducing carbonmonoxide, is further post-combusted in the melting cyclone 2 with oxygencontaining gas supplied to the melting cyclone. Iron oxide supplied tothe melting cyclone via apparatus 13 is pre-reduced approximately to FeOand at least partly melted. The pre-reduced iron oxide 14 then falls orflows down into the metallurgical vessel 1. When the metallurgicalvessel is upright the central axis extends essentially verticallythrough the centre of the vessel.

During operation the lances extend to above the slag layer 10 and thelances are adjustable in height so they can be positioned optimally forsupplying oxygen containing gas even when the vessel is at varyinglevels of fullness. The lances 3 are inclined from the vertical and theend portions 8 are configured to direct a jet 7 or jets of oxygencontaining gas towards the centre of the vessel either at the sameinclination of the lance or at greater angle from the vertical than theinclination of the lance.

FIG. 5 shows in detail the end portion 8 of a lance 3 having four ports17 which emit four jets 18 of oxygen containing gas. The lances 3 arepositioned so that their ends are all of equal distance from thesidewall. The number of lances projecting into the vessel can be varieddepending on the size of the metallurgical vessel and the surface areaof slag covered by each lance. The number of ports in the end portion ofthe lances can also be varied.

FIG. 2 shows the positions of the three feed chutes 12 with respect tothe three oxygen lances 3 of FIG. 1.

FIG. 3 shows a section of the vessel 1, a lance 3 projecting into thesection of the vessel and the trajectories 15 of coal particles added tothe vessel. The advantage obtained by adding coal particles a shortdistance from the lances is clear as the particles are entrained towardsthe slag layer with the substantially downward flow of post-combustedgases at the sidewall of the vessel. In contrast, FIG. 4 shows thetrajectories 16 of coal particles added between the lances. It can beseen that the majority of the particles are entrained in the upwardlydirected flow of post-combusted gases in the centre of the vessel andleave the vessel. A significant proportion of the coal particles addedthus never become available as reactants in the slag layer.

FIG. 6 shows a metallurgical vessel 1, a melting cyclone 2 (details notshown) and a plurality of lances 3, of which two are shown. The lances 3project into the vessel through the roof 6 and are configured to createa downwardly directed flow of the post-combusted gas at the sidewall 5of the vessel and an upwardly directed flow of post combusted gas in thecentre of the vessel 9. The lances 3 are inclined from the vertical andthe end portions 8 are configured to direct a jet 7 or jets of oxygencontaining gas towards the centre of the vessel either at the sameinclination of the lance or at greater angle from the vertical than theinclination of the lance. The side wall 5 of the metallurgical vesselcomprises an upper portion 21 and a lower portion 20. The lower portion20 accommodates the molten metal bath 11 and part of the slag layer 10in use. The upper portion 21 accommodates the remainder of the slaglayer in use and the lances 3 project into the upper portion of thevessel and supply oxygen containing gas to the slag layer 6 in the upperportion 3 of the vessel. A plurality of tuyeres 22 (of which two areshown) are arranged around the circumference of the lower portion of thevessel suitable for supplying gas and/or liquid and/or solids (such asrecycled dust) and/or plasma into the slag layer in the lower portion 20of the vessel. The number of tuyeres arranged around the circumferenceof the lower part of the vessel can be varied depending on the size ofthe vessel and the performance parameters of the tuyeres. The tuyeresmay comprise oxy-fuel burners. The remainder of the details in FIG. 6are in accordance with and numbered as the features illustrated in FIGS.1-5 and described above.

FIG. 7 shows the alternative metallurgical vessel 31 and a meltingcyclone 38. Details of the melting cyclone are not shown. Themetallurgical vessel itself comprises a lower portion 32 whichaccommodates the iron bath 39 and part of the slag layer 36 andcomprises at least one tap hole 41 for tapping off molten iron and slag.The vessel also comprises an upper portion 33, which accommodates theremainder of the slag layer 36, and a roof portion 34. The slag layer 36thus rests on top of the iron bath 39 and extends from the lower portionof the vessel 32 into the upper portion 33. Pre-reduced iron oxide 40falls or flows from the melting cyclone into the metallurgical vesseland is finally reduced in the slag layer. A plurality of lances 35supply oxygen containing gas to the slag layer 36 in the upper portion33 of the vessel. Two lances are shown in the figure but more may bepresent depending on, for example, the size of the vessel and theperformance parameters of the lances. A plurality of tuyeres 37 arearranged around the circumference of the lower portion of the vessel.The tuyeres are suitable for supplying gas and/or liquid and/or solids(such as recycled dust) and/or plasma to the slag layer in the lowerportion 32 of the vessel. The number of tuyeres arranged around thecircumference of the lower part of the vessel can be varied depending onthe size of the vessel and the performance parameters of the tuyeres.The tuyeres may comprise oxy-fuel burners. During the final reduction ofthe pre-reduced iron oxide a process gas comprising reducing CO isproduced that is partially post-combusted above the slag layer 36 in thevessel 31, whereby heat needed for the final reduction is released. Thereducing process gas rises and is further post-combusted in the meltingcyclone 38 with oxygen containing gas supplied to the melting cyclone.Iron oxide supplied to the melting cyclone is pre-reduced approximatelyto FeO and at least partly melted in the melting cyclone. Thepre-reduced iron oxide 40 then falls or flows down into themetallurgical vessel 31. While the invention has been illustrated by aparticular embodiment, variations and modifications are possible withinthe scope of the inventive concept.

1. Metallurgical vessel for iron and steel making comprising a bottomportion, a sidewall and a lance arrangement of at least two lances forsupplying oxygen containing gas to the interior of the vessel inoperation wherein each lance comprises an end portion for emittingoxygen containing gas wherein the lance arrangement is configured so asto achieve in operation a substantially downwardly directed flow ofpost-combusted gases at the side wall of the vessel and a substantiallyupwardly directed flow of post-combusted gases in the centre of thevessel.
 2. Metallurgical vessel according to claim 1, wherein at leastone of the lances is provided with means for emitting a plurality ofjets of oxygen containing gas from its end portion.
 3. Metallurgicalvessel according to claim 1, wherein at least one of the lances projectsthrough a roof portion of the metallurgical vessel.
 4. Metallurgicalvessel according to claim 1, wherein at least one lance is arranged todirect the oxygen containing gas towards a central axis of themetallurgical vessel.
 5. Metallurgical vessel according to claim 4,wherein at least one of the lances is inclined from the vertical under afirst acute angle with its end portion inclined towards the central axisof the metallurgical vessel.
 6. Metallurgical vessel according to claim5, wherein the end portion of the lance is configured to direct theoxygen containing gas towards the central axis of the metallurgicalvessel under a second acute angle from the vertical which second acuteangle is greater than the first acute angle.
 7. Metallurgical vesselaccording to claim 1, wherein the end portions of the lances are all ofequal distance from the sidewall.
 8. Metallurgical vessel according toclaim 1, wherein the metallurgical vessel comprises three or morelances.
 9. Metallurgical vessel according to claim 1, wherein through atleast one feed chute, particulate material is added to the vessel in thesubstantially downwardly directed flow of post-combusted gases. 10.Metallurgical vessel according to claim 9, wherein a plurality of feedchutes project through a roof portion of the metallurgical vessel. 11.Metallurgical vessel according to claim 9, wherein each lance has acorresponding feed chute.
 12. Metallurgical vessel according to claim11, wherein each feed chute is positioned between the lance and thesidewall of the metallurgical vessel in a radial direction. 13.Metallurgical vessel according to claim 1, wherein the sidewallcomprises a lower portion for accommodating a molten metal bath and aslag layer and an upper portion for accommodating a slag layer andwherein the at least two lances for supplying oxygen containing gas tothe upper portion of the vessel project into the upper portion of thevessel and wherein a plurality of tuyeres for supplying gas and/orliquid and/or solids and/or plasma into the slag layer in the lowerportion of the vessel are arranged around the circumference of the lowerportion of the vessel.
 14. Metallurgical vessel according to claim 13,wherein the diameter of the lower portion of the vessel is smaller thanthat of the upper portion.
 15. Metallurgical vessel according to claim13, wherein the tuyeres comprise oxy-fuel burners.
 16. Metallurgicalvessel according to claim 1, comprising a melting cyclone positionedabove and in open connection with the metallurgical vessel. 17.Metallurgical vessel according to claim 16, wherein the lances arepositioned to avoid contact with molten material passing downwards fromthe melting cyclone to the metallurgical vessel.
 18. Method of reducingiron oxides into iron using a metallurgical vessel in accordance withclaim 1, comprising the steps of supplying iron oxides to the vessel andreducing the iron oxides by supplying carbonaceous material to thevessel and supplying oxygen containing gas to the iron oxides via thelances.
 19. Method of reducing iron oxide to iron using a metallurgicalvessel in accordance with claim 1, comprising the steps of supplyingiron oxide to the vessel, supplying oxygen containing gas to the upperportion of the metallurgical vessel via the lances, supplyingcarbonaceous material to the iron oxide and supplying gas and/or liquidand/or solids and/or plasma into the slag layer in the lower portion ofthe vessel via the plurality of tuyeres.
 20. Method of reducing ironoxide according to claim 19, wherein the tuyeres comprise oxy fuelburners acting as a direct heat source in the slag layer in the lowerportion of the metallurgical vessel.
 21. Method of iron making using ametallurgical vessel in accordance with claim 1, comprising the stepsof: conveying iron oxide or pre-reduced iron oxide into themetallurgical vessel supplying oxygen containing gas to themetallurgical vessel via a lance arrangement of at least two lancesconfigured so as to achieve in operation a substantially downwardlydirected flow of post-combusted gases at the side wall of the vessel anda substantially upwardly directed flow of post-combusted gases in thecentre of the vessel, supplying carbonaceous material to the vessel. 22.Method according to claim 21, comprising the steps of: conveyingiron-oxide containing material into a melting cyclone, pre-reducing saidiron-oxide containing material by means of reducing post combusted gasesoriginating from the metallurgical vessel, at least partly melting theiron-oxide containing material in the melting cyclone by supplyingoxygen containing gas to the melting cyclone and effecting a furtherpost combustion in said reducing post combusted gases, permitting thepre-reduced and at least partly melted iron-oxide containing material topass downwardly from said melting cyclone into the metallurgical vesselin which final reduction takes places and effecting the final reductionin the metallurgical vessel in a slag layer by supplying oxygencontaining gas to the metallurgical vessel, via the lances, andsupplying coal to the metallurgical vessel and thereby forming areducing gas and effecting at least partial post combustion in saidreducing gas in said metallurgical vessel by means of said oxygencontaining gas supplied thereto.
 23. Method of iron making according toclaim 21, comprising the step of: supplying through tuyeres gas and/orliquid and/or solids and/or plasma into a slag layer in a lower portionof the vessel.